The ability to use sensory information to shape motor programs is critical for language development in humans. Similarly, juvenile songbirds use auditory feedback from their vocalizations and memorized representations of tutor song to adjust their song production motor programs until they achieve stable song that resembles that their tutor. Several experiments will be performed in awake, singing birds using chronically implanted stimulating and recording electrodes to test the hypothesis that, in the process of song learning, auditory feedback and a sensory representation of tutor song concurrently activate a region of the neostriatum (HVc) implicated in sensory and motor integration of song-related activity. The hypothesis can be stated in terms f a linear model in which HVc activity during signing is the sum of 1) auditory responses to the bird's own vocalization, 2) activation of a sensory representation of the tutor song and 3) motor activity related to song production. The model will be tested by comparing auditory responses to tutor song and the birds own developing song presented along with activity evoked during singing and activity evoked during singing when auditory feedback to Hvc is concurrently eliminated by transient electrical stimulation of the ascending auditory pathway. The chronically implanted electrodes will enable a neurophysical analysis of developmental changes in auditory and motor representations in Hvc in individual subjects as song stabilizes and the importance of auditory feedback decreases.